Phonograph needle



March 2, 1954 F. C. HOLTZ, JR

PHONOGRAPH NEEDLE Filed April 20, 1950 .Wederz' Patented Mar. 2, 1954'2, 70,962 HO GK NETEJBPE: ite e eke m Jr -tee h Il assi n!!! 2 1! eibetfeeeeeseti e.

Application. Aprfl20 1950, Qeria} N9. 151,969 1.3 (01,

white inven i n elateste m no ra h needleml' mer articu a e henvetateh ee: having a flexible .seetinne m ov n the .9m;- nllianee o the needle,eis ne dbei g c stzue ed he prot et. t fl ible seetien g a r t bzzeake tOne-"featur a the invent en e th t t 9 tides en: mpflme pho o aph eedle:anq er mature of the: mye ioe sha i P &- p m eemn e e l i g e; exi e een fer re idinee substan a amou t 01 Ye" e1 horizontal eemnl ee e andaving mean pre ectin the. e ibl ee i n a eine WeeR eQ e f. the: eetueeef: inv nti n ie the? t flexible eeetion eem me a m; W 0 e0 speeee el sexte e when th .Qeeh t e h nk Qt t neee v ee elw t e eve e e? on i unale ie er qi"; il-1: ne he feete r 91 the inventie i t at at Re enee aiW en the onpq 1 f s qlm eiiethe r said e ete the- 19% e ee eeeine few ateesfie e flexible;e nneetmes r et l eb e w yeta furthe ieetu e f he iev'm Eh shank 59- than? the QOQQQQ e parall l: he the e er lee-"we fleeibleemi ti e i rise t e tiv pteierebli hem a tetlkp ee i meme;- iJ Fi1 eand??? mum thickness of the order of 0.01 11105,,

Q-Plee t n eand a a t -p i) e e tign. will be apparent. i em theiollbwine Speci'fi: eetien and fipom the drawings, in which:

Fig.1 is a, iregmentary side elevation of' e. t'qne gnm-Ieaprymg a;neegi leucenetmctecf in. ecc ragit e wt he 'nventiem. the tipof theneedle. engaging het ieee re er i- F-ig', g' ;is'. an enlarged side.elevational view of t e nee e f- 'Ei 11 remq e fiem t rm; ie 3- ise l eetwn i w Ofthe me u? owe-2 Qkine r the H er- 0f? .Figflfilis afragmentary sideeleva'tibxiali View 0i a mddifi m needle; and

i e s de el vafiqne ew Q? the ne dl 15 li q inef f om h le t the ee Iithe newd s f s un rom Ph ne'- grekpf r record; petrtien'iafly" from a}iaterell'y cut iecord 'whieh the undulations representmgtfie rattle: 0t.monographs which emplpy a; rigid dle. In; additiejn', a needle.havine'suchverticali mpliance willelso lessen sflzfialie'd ---need;1etent" and other. sunfacer nuises which: reaeh the. ear directly item;the needle without being. trans-q v mitt-ed theme-1e the amplifyingystemassqeiateel with the phonograph. To achieve; satisfactory vert ealcemel-ieneeetzhe needle w v eh transmits vibrq. inn tn the 61YI123120Fother. translating; de;-' e nertienwhieh is thin atmane' substantially 1eshank. efitheneed le. It des mhl t0: pt vide means to pr tect suchaflexible pe tie I ene e ka e or detonmation he eventthe nee le is,"mppee .112130; the netiord I gurfaw Q3 1. ithershoqlset I have-heretel-rfor inY n-te nhone teen needl s havin a: uard: de e- 'D J .e fi theneedl structure and wh ch er q meteet t e needl ee in S ch eak e.defierm ion, need es 6 thi shame:- elaime i n e ndine v 3-. 93327 filedAp l 1 .1948; ate 2 553 882; Se iefl No 51:62: ed Au us v lees, ndSerial: Ne- 5. ;8'5 fi d;- eetebe flt 18% Y- In the e tiethen attemptshave beenmede-tq pro ide phonperenhneedles he -ineventi a i com: F e -meby efise fiine the recerd en in t p the needle at the end gf' atnelativelylong spring; member whi h; extends e cen iderable distancefinom the axis: of theshanle 01' the needle; A dis; adyantage ofl such:an, arrangement is that when? the? recqid': engaging; tip?- spaeedi a;considerable; distance f rom the shen'kiw change mm the angle of the:tone caluees a substantial ehange in the; angle atzwmch the needle ti p'engages the; groove 3 will be considerably different than when ten ortwelve records are on the turntable. Furthermore, such an arrangementlocates the center of gravity of the needle a considerable distance fromthe shank, and the needle has an undesirable action in responding tocertain forces, the inertia effects of this arrangement causingsluggishness.

Another desirable feature in a phonograph needle is a considerabledegree of horizontal compliance, particularly in the direction of therecord groove. Prior to my inventions needles which provided a bumper toprotect the flexible portion against breakage had only limitedhorizontal compliance because the extension or foot which provided thebumper added considerable additional mass to the needle; and otherneedles having a flexible portion in the form of a horizontallyextending loop, while providing more horizontal compliance, have hadundesirable features in that forces in the direction of needle traveldevelop torque in the needle.

I have devised and am herewith disclosing and claiming an improvedphonograph needle which possesses desirable advantages of vertical andhorizontal compliance together with means for protecting the flexiblesection without any of the disadvantages noted above, and which isfurther advantageous in that the needle is so constructed that it has noportions which extend outwardly away from the shank and the mass of theneedle is no greater than that of an ordinary rigid needle having noflexible section.

Referring now to the drawings, in Fig.1 a tone arm It) carries a needlegenerally designated at II in a chuck (not shown), and the needle ridesin a groove upon the surface of a phonograph record 12. The needle isresponsive to undulations in the groove and transmits them as vibrationsto a crystal or other translating device.

In conventional operation the vibrations are translated into electricalvariations, are amplifled, and are reproduced by means of a speaker orother transducer. In Figs; 2 and 3 the needle of Fig. 1 is shownenlarged and removed from the tone arm chuck. The needle comprises anelongated shank and a terminal tip portion l9. The shank has an upperrelatively rigid portion l3, which is generally cylindrical in shape anda flattened portion I4 which extends on the upper end of the shank alongone side for a substantial portion of the length of the shank. Thisflattened portion serves to indicate the front side of the shank so thatthe needle may be properly positioned in the tone arm chuck, and inaddition the-flattened portion cooperates with the holding end of a setscrew or other holding device on the tone arm so-that the needle may beheld immovably in the tone arm chuck.

The shank-also includes a lower flexible portion formed by a pluralityof closely spaced narrow parallel slots l5 and [6, each extending morethan half way through the shank generally transversely of thelongitudinal axis thereof. The slots are cut on opposite sides of theshankand are cut in the direction of the record groove when the needleis in operating position, and a flexible connecting strip I1 is providedbetween the slots. Preferably, the slots are cut in front and rear wallsof a widened portion 18 having flattened side walls 18a and [81). Asshown in Fig. 3 the distance between the flattened sides is less thanthe width of the shank above the widened portion, and as shown in Fig. 2the dis tance between the front and rear walls of the widened portion isno greater than .twieethe because of the flexible strip l1.

width of the shank above the widened portion. Each slot has a thicknessof the same general order as the thickness of the connecting strip I1,and I prefer that each slot and the strip each have a minimum thicknessof the order of 0.006 inch and the maximum thickness of the order of0.01 inch. In the needle of Fig. 2 the slots may each be 0.008 inchthick and the strip I! may be 0.0115 inch thick. I prefer that the slotsbe cut at an angle of between 65 and 75 to the axis of the shank so thatthe connecting strip is substantially parallel to the record surfacewhen the needle is mounted in operating position. In most conventionaltone arms the needle extends at an angle of approximately 21 to therecord surface. This construction also provides a relatively longconnecting strip H without adding to the mass of the needle. I alsoprefer that the bottom slot l6 be shorter than the top slot 15 so thatthe portion shown at 20 in Fig. 2 is thicker than the portion shown at2! in said Fig. 2. With this construction, upon abnormal flexure of theneedle (as for example if the tone arm is dropped) the relatively thickportion 20 will prevent the tip IQ of the needle from being bent out ofline with the axis of the shank. In the event the tone arm is droppedthe upper slot 15 closes momentarily at its outer end and the thinflexible strip i1 is put under tension like a spring connected to theportion 2|. When the abnormal pressure is released the flexible stripreturns to its normal position as shown.

A needle constructed in accordance with the invention possessesexcellent vertical compliance Satisfactory lateral compliance is alsopresent in the needle because of the flexible strip, and consequentlythe needle tracks properly in the record groove and has a relativelyhigh output. Compliance to horizontal forces in the direction of therecord groove is obtained due to the relatively thin portion 21, and thegood overall compliance of the needle insures a low level of surfacenoise and needle talk. In addition, the normally spaced portions at theouter ends of the slots which are adapted to abut in the event theneedle is droppedor is subjected to other abnormal pressure, providemeans for guarding against breakage or deformation of the flexible stripwithout adding any mass or bulk to the needle. In fact, a needleconstructed in accordance with this invention will have less mass thanan ordinary rigid needle because a small part of the needle is removedwhen the slots are cut. A needle constructed in accordance with theinvention will provide good pickup at desired audio-frequencies and willattenuate frequencies in excess of 6,000 cycles per second.

Referring now to Figs. 4 and 5, the shank 23 of the needle may haveflattened sides 24 near its lower tip extremity 3i, and a lower flexibleportion is formed by a spaced pair of parallel slots 25 and 26, eachextending more than half way through the shank from one side thereofgenerally transversely of the longitudinal axis thereof. A center slot21 extends from the other side of the shank between the pair of slots toprovide two spaced parallel flexible connecting strips 28 and 29.Preferably, the bottom slot has a rounded end facing in a directioncounter to the direction of record travel, and the center slot 27preferably is shorter than the upper and lower slots to provide arelatively heavy solid portion 30 which may act as a bumper in the eventthe needle is dropped. In this needle, as;

gara es Welles inthe needle-of-Fig2, the flattened por tion. is notnecessary but by providing such a flattened. portion better lateralcomplianceis achieved. The needle of Figs. 4 and 5 hasthe sameadvantages as-the needle of Fig. 2 but I prefer the needle of" Fig. 2because it is more simple to manufacture.

While many variations may be made-in the dimensionsof the needle, Ihavefoundthat a suitable needle' may have a shank with a diameter of Ia-inch, and the flattened portion ldof'tlie needle oi Fig. 2 may have awidth of ilgllllincli at its widestpart. Inthe needle of Fig.2, theportion lt may be 0.025 inch thickand the portion 20 may bra- 0.030-inch 7 thick. 1 The widened poition l8 near the tip end of the needlemay be of the order of inch long and may be of the order of 0.030 inchwide.

While I have shown and described certain embodiments of my invention, itis to be understood that it is capable of many modifications. Changes,therefore, in the construction and arrangement maybe made withoutdeparting from the spirit and scope of the invention as disclosed in theappended claims.

I claim:

1. A phonograph needle of the character described comprising: a straightelongated shank having an upper relatively rigid portion and a lowerflexible portion formed by a plurality of closely spaced narrow parallelslots, at least some of which extend more than half way through saidshank generally transversely of the longitudinal axis thereof, at leastone of said slots being on the opposite side of said shank from anotherof said slots to provide at least one flexible connecting striptherebetween; and a terminal tip portion extending from the bottom ofsaid shank.

2. Apparatus of the character claimed in claim 1, wherein said slots arecut at an angle of between 65 degrees and '75 degrees to the axis ofsaid shank and said connecting strip is substantially parallel to therecord surface when the needle is mounted in operating position.

3. Apparatus of the character claimed in claim 1, wherein said slots arecut in front and rear walls of a portion of the shank having flattenedside walls, the distance betwen the flattened sides being less than thewidth of the shank above said portion, and the distance between saidfront and rear walls being no greater than twice said width.

4. Apparatus of the character claimed in claim 1, wherein said slots areequally spaced from each other, each slot and each connecting striphaving a minimum thickness of the order of 0.006 inch and a maximumthickness of the order of 0.01 inch.

5. A phonograph needle of the character described, comprising: astraight elongated shank having an upper relatively rigid portion and alower flexible portion formed by a plurality of closely spaced narrowparallel slots each extending more than half way through said shankgenerally transversely of the longitudinal axis thereof, at least one ofsaid slots being on the opposite side of said shank from another of saidslots to provide at least one flexible connecting strip therebetween andsaid slots being cut in front and rear walls of a widened portion of theshank having flattened side walls, the distance between the flattenedsides being less than the width of the shank above said flattenedportion and the distance between said front and rear walls being nogreater than twice said width,

each slo'thavinga thickness or the. same orderi'as the thickness ofsaid. connecting strip; and a terminal tipportion extending from" thebottom of said shank, the inassof the needle beingsub stantialiy equallydistributed about its. longi tudinal axis. 6. Aphon-ograph needle of thecharacterde! scribed, comprising: an elongated shank having upperrelatively rigid. portion and a lower flexible: portion formed by alpairof. parallel slots each extending more than halfway through said shankfrom opposite sides =thereoiigenerallytransversely of thelongitudinalaxis thereof to provide a flexible connecting strip having athieknesspf the order 0130.006 inch: and a:-maximum thickness of theorder of 0.01 inch, one of said slots being cut in the direction ofrecord movement; and a terminal tip portion extending from the bottom ofsaid shank.

7. Apparatus of the character claimed in claim 6, wherein the shank isstraight and the lower slot is shorter than the upper slot to preventbending of said terminal tip.

8. Apparatus of the character claimed in claim 6, wherein the shank isstraight and said slots are cut at an angle of between degrees and 75degrees to the axis of said shank and said con- 7 necting strip issubstantially parallel to the record surface when the needle is mountedin operating position, and wherein the thickness of each slot issubstantially equal to the thickness of the connecting strip, the massof the needle being substantially equally distributed about itslongitudinal axis.

9. A phonograph needle of the character described, comprising: anelongated shank having an upper relatively rigid portion and a lowerflexible portion formed by a spaced pair of parallel slots eachextending more than half way through said shank from .one side thereofgenerally transversely of the longitudinal axis thereof, and a centerslot extending from the other side of said shank between said pair ofslots to provide two spaced parallel flexible connecting strips; and aterminal tip portion extending from the bottom of said shank.

10. Apparatus of the character claimed in claim 9, wherein the centerslot is shorter than said pair of slots to provide a relatively largeintermediate portion interconnecting said flexible strips.

11. A phonograph needle of the character described, comprising: astraight elongated shank having an upper relatively rigid portion and alower flexible portion formed by a spaced pair of parallel slots eachextending more than half way through said shank from one side thereofand generally transversely of the longitudinal axis thereof and a centerslot extending from the other side of said shank between said pair ofslots to provide two spaced parallel flexible connecting strips, saidslots being cut in front and rear walls of a portion of the shank havingflattened side walls, the distance between the flattened sides beingless than the width of the shank above said portion, and the distancebetween said front and rear walls being no greater than twice saidwidth, and said slots being equally spaced from each other, each slotand each connecting strip having a minimum thickness of the order of0.006 inch and a maximum thickness of the order of 0.01 inch; and aterminal tip portion extending from the bottom of said shank, the massof the needle being substantially equally distributed about itslongitudinal axis.

12. A phonograph needle of the character described, comprising: astraight, elongated shank having an upper relatively rigid portion anda. lower flexible portion formed by a plurality of slots extendingpartially through said shank generally transversely of the longitudinalaxis thereof, at least one of said slots being on the opposite side ofsaid shank from another of said slots andsaid slots overlapping to format least one flexible connecting strip therebetween, the mass of theneedle being substantially equally distributed about its longitudinalaxis; and a terminal tip portion extending from the bottom of saidshank.

- 13. Apparatus of the character claimed in claim 12, wherein said slotsand said strip eachhave a minimum thickness of the order of 0.006inchand a maximum thickness of the order of 0.01 inch.

FREDERICK C. HOLTZ, JR. f

References Cited in the file of this patent UNITED STATES PATENTS

